The present invention relates to an advanced burr, appliqué for a burr and method of fabricating. Burr and abrading tools are well known in the medical and manufacturing industries. These tools are used to remove various materials, usually in finish or “fine” work where careful control of amount of material removed is important. Also, these tools must not damage surrounding tissue or machined surfaces either by impact with the surface or by leaving behind particles removed from the tool during abrading operations. Particles released from the tool at high speed also present a safety hazard to the operator.
One well known manufacturing technique is to machine flutes or cutting surfaces in a burr or abrader surface. When operated in a rotational or oscillatory mode, these flutes dig into the object surface and scrape material off. Two problems with this technique are (1) a “kickback” effect when the flutes first make contact, and (2) limitation in flute size, shape and geometry as dictated by the machining process used to create the cutting surface on the burr. This kickback effect can damage surrounding tissue and other material, while size and shape limitations direct usage toward more coarse removal applications. Burr operational speed has been increased to minimize kickback, but this makes the burr more dangerous to use.
Another well known manufacturing technique is to attach hard particles to the tool surface, like diamonds and carbides, by electroplating and/or brazing. While this technique can minimize kickback effect by incorporating particle “randomness,” particle release has been and is a problem. In electroplating diamonds, for example, attachment is mechanical rather than metallurgical. Particle release from impact is random since it depends on how much of the diamond particles are covered by the plating. Also, diamonds are subject to fracture on impact, depending on crystal orientation, as demonstrated by the diamond cutting process. Carbides are also subject to fracture. When these tools wear, it is by loss of particles from fracture and release, rather than dulling from deformation. Particularly in surgical applications, even small amounts of these foreign particles that are not recovered can be detrimental to patient health by causing inflammation and sometimes resulting in failure of surgical results, such as when the procedure involves joint replacement failure due to “osteolysis.” Osteolysis is a medical term denoting inflammation due to presence of foreign particles. Approximately 20% of total joints eventually fail due to onset of osteolysis.
Applicants have sought to solve the problems of the prior art by developing a process for creating and applying a unique cutting surface to a burr or abrader tool. The resulting tools solve the problems described above. The inventive technique utilizes a continuous “appliqué” that has integral cutting facets. The cutting facets are engineered for a particular application rather than using generic particles or a machined surface. The appliqué is formed on the tool surface and then metallurgically bonded and metallurgically coated by the process known by the registered Trademark BRAZOL. This process has been successfully used for over a decade in the surgical industry and is described in U.S. Pat. Nos. 5,022,555; 5,149,597; 5,133,728; 5,135,533; and 5,707,276 all granted to Applicants. Bonding and coating may also be done by the “Cobalt-Phosphorous” technique described in U.S. Pat. Nos. 5,358,547 and 5,649,994 granted to Applicant Holko. These patents are hereby incorporated herein by reference including the disclosures in these patents of numerous formulations of metallurgical bonding materials, each of which is incorporated by reference herein as if specifically set forth herein.